Mask blank glass substrate manufacturing method, mask blank manufacturing method, mask manufacturing method, mask blank glass substrate, mask blank, and mask

ABSTRACT

A method of manufacturing a mask blank glass substrate includes a marking step of irradiating laser light onto a mirror-like surface in an area, having no influence on transfer, on a surface of the mask blank glass substrate to thereby form a pit that is used as a marker for identifying or managing the mask blank glass substrate.

This application claims priority to prior Japanese patent applicationsJP 2005-96976 and JP 2005-377140, the disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to a mask blank glass substrate manufacturingmethod, a mask blank manufacturing method, a mask manufacturing method,a mask blank glass substrate, a mask blank, and a mask.

Conventionally, a mask blank, in which an optically readable area codeis provided in the form of a metal film formed on an end surface or aback surface of a glass substrate, is known. (see, e.g. JapaneseUnexamined Patent Application Publication (JP-A) No. 2002-116533).Further, a mask blank, in which predetermined symbols are marked on aside surface (end surface) of a glass substrate at its frosted portion,is also known (see, e.g. Japanese Unexamined Patent ApplicationPublication (JP-A) No. S59-15938).

In recent years, the wavelength of an exposure light source has beenreduced to 200 nm or less. Therefore, the quality (e.g. the allowablesize of a defect, the allowable number of defects, or the in-planethickness uniformity of a resist film that affects patterncharacteristics of a device) required for a mask blank glass substrateor a mask blank has been becoming higher and higher. Depending on themanner of formation of an area code or the like, dust may be generatedin a later process. Thus, it possibly becomes difficult to satisfy therequired quality. Further, depending on the manner of formation of anarea code or the like and the position of the formation thereof, thein-plane thickness uniformity of a resist film formed by the spincoating method may be degraded. Thus, it possibly becomes difficult tosatisfy the required quality. Particularly, in the case of a thin resistfilm having a thickness of 300 nm or less for miniaturization of apattern in recent years, the influence exerted on the pattern formationdue to variation in in-plane thickness increases than ever before and,therefore, the problem becomes more conspicuous. Further, also endsurfaces are often mirror-polished in a mask blank glass substrate inrecent years. Therefore, it is often difficult to obtain sufficientreading accuracy from lustered symbols or the like.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a mask blankglass substrate manufacturing method, a mask blank manufacturing method,a mask manufacturing method, a mask blank glass substrate, a mask blank,and a mask that can solve the foregoing problems.

For accomplishing the foregoing object, this invention has the followingstructures.

(Structure 1)

A method of manufacturing a mask blank glass substrate, comprising:

a marking step of irradiating laser light onto a mirror-like surface inan area, having no influence on transfer, on a surface of the mask blankglass substrate to thereby form a pit that is used as a marker foridentifying or managing the mask blank glass substrate.

The marking step forms the mark, for example, in a peripheral area,having no influence on transfer, on a main surface, where a mask patternthin film is not formed, of the glass substrate, on a side surface,having no influence on transfer, of the glass substrate, on a chamferedsurface formed between the main surface and the side surface, at a notchmark of the glass substrate, or the like. The marking step forms thepit, for example, by melting or sublimating part of the mirror-likesurface of the glass substrate by irradiation of the laser light. Themarker thus formed ensures the sufficient reading accuracy and has nopossibility of generating dust in a later step.

The marker can be used, for example, as identificationinformation/identification symbols (identification code) or managingsymbols (managing code) unique to the manufactured mask blank glasssubstrate.

This enables one-by-one management of mask blank glass substrates thatcannot be achieved conventionally.

Further, this identification information can be correlated, for example,with information (substrate information: defect information, surfaceform information such as surface roughness or flatness, shape such asthickness or size, or the like) obtained in the manufacturing step orunique substrate information (material, component, composition, purity,birefringence, transmittance, or the like) possessed by the glasssubstrate. This makes it possible to reliably achieve correlationbetween the obtained or prepared information and the mask blank glasssubstrate.

In place of or in addition to the marker indicative of theidentification information/identification symbols or the managingsymbols, the marking step may form a marker directly representing thesubstrate information obtained in the manufacturing step, the uniquesubstrate information possessed by the glass substrate, or the like.Also in this case, one-by-one management of mask blank glass substratescan be properly carried out.

As a material of the glass substrate, use can be made of, for example, asynthetic quartz glass or a SiO₂—TiO₂-based multicomponent glass.According to the material of the glass substrate, a selection is made ofa wavelength of laser light for melting or sublimating part of the glasssubstrate by irradiation of the laser light to thereby form a pit. Inthe case of the foregoing material of the glass substrate, the markingstep can form the marker, for example, by a laser marker using a carbondioxide (CO₂) gas laser. The part of the surface of the glass substratecan be suitably melted or sublimated by properly adjusting the energy ofthe laser light and the pit formed by the melting or sublimation can beread with high accuracy. Further, it is also possible to suppressgeneration of cracks due to aged deterioration. It is also possible thatthe marking step forms a plurality of pits by irradiating the laserlight a plurality of times onto each of positions that will be the pits.This can reduce variation in shape of the plurality of pits. Thus, thereading accuracy of the marker can be improved. The plurality of pits,for example, may form respective points of a two-dimensional code suchas a data matrix or a QR code or may be a hidden code or a random numbercode for preventing a third party from understanding information of themarker.

Unless the selection is made of the proper wavelength of the laser lightaccording to the material of the glass substrate, the portion where thelaser light is irradiated is, for example, formed with a crack-likemarker. In this case, the crack-like marker undesirably causesgeneration of dust.

Further, by forming the marker on the side surface of the glasssubstrate, on the end surface of the glass substrate such as thechamfered surface, or at the notch mark of the glass substrate, it canbe prevented that a new defect or the like is generated on the mainsurface of the glass substrate or the mask pattern thin film formed onthe main surface due to the formation of the marker. Further, since themarker can be deleted by end-surface polishing or the like, even when,for example, necessity occurs to change the marker, a new marker can beformed without reducing the thickness of the glass substrate.

The marking step is carried out, for example, before lapping/polishingthe glass substrate such as at the time of receiving the glass substrateor after performing the lapping/polishing and a substrate inspection.The marking step may be carried out during each step of thelapping/polishing, for example, after lapping the glass substrate, afterend-surface polishing the glass substrate, or after mirror-polishing themain surfaces of the glass substrate. When the marking step is carriedout before the substrate inspection, for example, a marker indicative ofidentification information/identification symbols or managing symbols ofthe glass substrate is formed.

Further, for example, when precise polishing and ultra-precise polishingare carried out in the end-surface polishing of the glass substrate, themarking step may be carried out between the precise polishing and theultra-precise polishing with respect to the end surfaces. This canreduce the surface roughness of the inside of the marker and the endsurface other than the marker and thus is more effective for preventinggeneration of dust. The precise polishing is, for example, polishingthat is carried out by the use of a polishing solution containing ceriumoxide and a solvent such as water and a polishing brush or a polishingpad. The ultra-precise polishing is, for example, polishing that iscarried out by the use of a polishing solution containing colloidalsilica and a solvent such as water and a polishing brush or a polishingpad. The marking step may be carried out, for example, on the mainsurface of the glass substrate between precise polishing andultra-precise polishing. In this case, since the ultra-precise polishingof the main surface is carried out after the formation of the marker, itis possible to further reduce a possibility that the marker causesgeneration of dust.

(Structure 2)

A method according to Structure 1, further comprising:

a step of preparing substrate information about the mask blank glasssubstrate,

wherein the substrate information is is correlated with the marker.

This makes it possible to directly correlate the substrate informationsuch as information about surface shape, flatness, and defect of theglass substrate with the glass substrate.

The preparation of the substrate information about the glass substraterepresents preparation of substrate information obtained in themanufacturing steps or unique substrate information possessed byindividual glass substrates. For example, the substrate informationobtained in the manufacturing steps includes substrate informationobtained in a substrate inspection step.

The substrate inspection step checks, for example, the thickness, thesurface shape (the warp shape of the main surface or the convex-concavestate of the entire main surface), the flatness, the degree ofparallelization, and so on with respect to the shape of the main surfaceof the glass substrate. This makes it possible to efficiently carry out,for example, a film forming step of forming a mask pattern thin film(e.g. phase shift film, light-shielding film, or the like) inmanufacturing a mask blank.

Further, the substrate inspection step checks, for example, theposition, kind (convex defect (particles or the like), concave defect(pinholes, cracks, or the like) or the like), and size with respect tothe defect of the main surface of the glass substrate. If such defectdata is known, for example, a mask pattern can be designed so as toavoid the defect upon manufacturing a mask.

(Structure 3)

A method according to Structure 2, wherein:

the substrate information is information including at least one ofphysical properties, chemical properties, optical properties, a surfaceform, a surface shape, a material, and a defect of the mask blank glasssubstrate.

As the physical properties of the glass substrate, there is cited, forexample, birefringence, refractive index absorption coefficient, or thelike. As the chemical properties of the glass substrate, there is citedacid resistance, alkali resistance, or the like. As the opticalproperties of the glass substrate, there is cited absorptioncoefficient, transmittance, or the like. As the surface form of theglass substrate, there is cited surface roughness, waviness, flatness,degree of parallelization, convex shape, concave shape, or the like. Asthe shape of the glass substrate, there is cited thickness, size, or thelike. As the material of the glass substrate, there is cited glass type,composition, or the like. As the defect of the glass substrate, there iscited a defect inside the substrate such as striae, bubbles, orabnormality in transmittance due to the incorporation of impurities, adefect on the surfaces of the substrate such as particles, cracks, orpinholes, or the like. As described above, with respect to the defect ofthe glass substrate, by adding the information such as the position orsize of the defect in the glass substrate in addition to the foregoingkinds of defects, it is possible, for example, to design a mask patternso as to avoid the defect upon manufacturing a mask or to deal with itby applying the glass substrate to a mask blank with a grade in whichthe defect is not questioned or a mask blank adapted for use in arelatively long wavelength region.

(Structure 4)

A method of manufacturing a mask blank, comprising:

a film forming step of forming a mask pattern thin film on a mainsurface of the mask blank glass substrate obtained by the methodaccording to Structure 1.

With respect to mask blanks, there are a plurality of grades withdifferent qualities depending on exposure wavelengths or uses (formationpatterns). The allowable size of a defect, the allowable number ofdefects, or the like differs depending on the grade. Further, there area plurality of kinds of mask pattern thin films (phase shift film,light-shielding film (opaque film), and so on) and resist films that areformed in the manufacture of mask blanks. Therefore, it is not easy tomanage the grades and the kinds of thin films and resist films to beformed, in the manufacture of mask blanks.

However, according to Structure 4, it becomes possible to performone-by-one management of the mask blanks. Therefore, the grades and thekinds of thin films and resist films to be formed can be properlymanaged in the manufacture of the mask blanks. The marker represents,for example, identification information/identification symbols ormanaging symbols of the mask blank glass substrate. The identificationinformation/identification symbols or the managing symbols arecorrelated, for example, with the kind of a mask blank to be formed bythe mask blank glass substrate. Further, since the mask blanks can bereliably one-by-one managed, when, for example, supplying theinformation about the mask blanks to a mask maker or the like along withthe mask blanks, it is possible to reliably carry out the correlationbetween the information and the mask blanks.

(Structure 5)

A method of manufacturing a mask blank, comprising:

a film forming step of forming a mask pattern thin film on a mainsurface of a glass substrate, and

a marking step of irradiating laser light onto a mirror-like surface inan area, having no influence on transfer, on a surface of the glasssubstrate to thereby form a pit that is used as a marker for identifyingor managing the glass substrate and/or a mask blank formed with the maskpattern thin film on the glass substrate.

According to Structure 5, it is possible to obtain the same effect asStructure 4. The marking step in Structure 5 may be carried out in theglass substrate manufacturing process as recited in Structure 1, but maybe carried out before or after forming the mask pattern thin film afterthe glass substrate manufacturing process.

(Structure 6)

A method according to Structure 5, further comprising:

a step of preparing substrate information about the glass substratebefore the film forming step, the marker being correlated with thesubstrate information, and

a thin film determining step of determining the mask pattern thin filmto be formed, based on the substrate information read from the marker,

wherein the film forming step forms the mask pattern thin filmdetermined in the thin film determining step.

This makes it possible to determine the kind of the mask pattern thinfilm to be formed in the film forming step, for example, depending uponthe substrate information in the step of preparing the substrateinformation (specifically, the inspection results of the substrateinspection step (the substrate inspection step that inspects at leastone of the surface shape, the flatness, and the defect of the mainsurface of the glass substrate). Therefore, the mask blank glasssubstrate can be effectively used without waste.

The thin film determining step, for example, identifies the surfaceshape of the main surface as the shape being one of the substrateinformation of the mask blank glass substrate. When a film stress existsin the mask pattern thin film, the surface shape, when the mask blank isformed, differs between the case where the surface shape of the mainsurface is concave and the case where it is convex. Thus, the thin filmdetermining step determines the kind and thickness of the mask patternthin film to be formed, taking into account the inspection results ofthe substrate inspection step. This makes it possible, for example, toimprove the yield as compared with the case where the kind of a maskpattern thin film to be formed in the film forming step has beendetermined in advance, or the like.

(Structure 7)

A method according to Structure 5, further comprising:

a thin film information preparing step of preparing thin filminformation about the mask pattern thin film after the film formingstep,

wherein the marker is correlated with the thin film information obtainedin the thin film information preparing step.

Specifically, the thin film information preparing step represents, forexample, a thin film inspection step that inspects the thin filminformation, such as at least one of the optical properties, the surfaceshape, and the defect, of the mask pattern thin film. This makes itpossible to directly correlate the thin film information of the maskpattern thin film such as the thin film information about the opticalproperties, the surface shape, the defect, or the like with the maskblank.

(Structure 8)

A method according to Structure 7, wherein:

the thin film information is information including at least one ofphysical properties, chemical properties, electrical properties, opticalproperties, a surface form, a material, a defect, and a film formingcondition of the mask pattern thin film.

As the physical properties of the thin film, there is cited, forexample, thermal expansion coefficient or the like. As the chemicalproperties of the thin film, there is cited acid resistance, alkaliresistance, water resistance, or the like. As the electrical propertiesof the thin film, there is cited resistivity or the like. As the surfaceform of the thin film, there is cited surface roughness, waviness,flatness, degree of parallelization, convex shape, concave shape, or thelike. As the material of the thin film, there is cited components,composition, composition distribution in a thickness direction orin-plane direction, or the like. As the defect of the thin film, thereis cited a defect such as abnormality in transmittance due to theincorporation of impurities, particles, or pinholes. As the film formingconditions of the thin film, there are cited a film forming apparatus,kind of gas, gas pressure, sputtering target information, gas flow rate,heating condition, film forming date, and so on. Like the defects of theglass substrate as described above, by adding information such as theposition or size of the defect in the thin film in addition to theforegoing kinds of defects, it is possible, for example, to design amask pattern so as to avoid the defect in the manufacture of a mask orto deal with it by applying the thin film to a mask blank with a gradein which the defect is not questioned.

As a manner of using the thin film information, the following usingmanner is specifically considered. The marking step forms the marker foridentifying the thickness of the mask blank glass substrate, the maskblank manufacturing method includes the thin film inspection step ofinspecting, for example, at least one of the optical properties, thesurface shape, and the defect being the thin film information of themask pattern thin film, the thin film inspection step includes apass/fail judging step of judging whether or not a specification of themask blank is satisfied, the mask blank manufacturing method furtherincludes a thin film stripping step of stripping the mask pattern thinfilm from the mask blank that has been judged not to satisfy thespecification of the mask blank, a thickness identifying step ofidentifying, by the use of the information read from the marker, thethickness of the mask blank glass substrate that has been stripped ofthe mask pattern thin film in the thin film stripping step, and arepolishing step of polishing the main surface of the mask blank glasssubstrate by a polishing amount determined according to the thicknessidentified in the thickness identifying step, and the film forming stepforms a new mask pattern thin film on the main surface of the mask blankglass substrate that has been polished In the repolishing step.

As a material of the mask blank glass substrate, for example, asynthetic quartz glass or a SiO₂—TiO₂-based multicomponent glass isused. Since such a glass is expensive, it is desirable that the glasssubstrate be effectively used without waste. According to the manner asdescribed above, even when a failure in formation of the mask patternthin film or the like occurs so that the specification of the mask blankis not satisfied, it is possible to efficiently recycle the mask blankglass substrate. By the use of the recycled mask blank glass substrate,a new mask blank can be properly manufactured. The mask blank glasssubstrate may be recycled as a mask blank glass substrate for a gradedifferent from that before the recycling, such as a lower grade.

Further, according to the manner as described above, since the thicknessof the glass substrate can be identified in the thickness identifyingstep, it is possible to simplify a thickness classification step beforethe repolishing. Moreover, according to the identified thickness, it ispossible to easily and properly set the polishing conditions such as thepolishing amount. The repolishing step, for example, sets a machiningamount according to the thickness and carries out polishing by thepolishing amount corresponding to the thickness. After the repolishingstep, for example, a marker for identifying the mask blank glasssubstrate is formed after the recycling. It is noted here that themarker of the mask blank glass substrate before the recycling can bedeleted, for example, by polishing in the repolishing step.

(Structure 9)

A mask blank manufacturing method according to Structure 5, furthercomprising:

a resist film forming step of forming a resist film on the mask patternthin film after the film forming step, and

a resist film information preparing step of preparing resist filminformation about the resist film,

wherein the marker is correlated with the resist film informationobtained in the resist film information preparing step.

According to Structure 9, it is possible to obtain the same effect asStructure 4. The resist film information preparing step specificallyrepresents, for example, a resist film inspection step of inspecting theresist film.

(Structure 10)

A method according to Structure 9, wherein:

the resist film information is information including at least one ofphysical properties, chemical properties, a surface form, a material, adefect, and a film forming condition of the resist film.

As the physical properties of the resist film, there is cited, forexample, hardness or the like. As the chemical properties of the resistfilm, there is cited acid resistance, base resistance, or the like. Asthe surface form of the resist film, there is cited surface roughness,waviness, flatness, in-plane thickness uniformity, average thickness,bird's-eye view of the resist film thickness, or the like. As thematerial of the resist film, there is cited resin material, molecularweight, kind of resist, or the like. As the defect of the resist film,there is cited convex defect such as particles, concave defect such aspinholes, or the like. With respect to the defect of the resist film, byadding information such as the position or size of the defect in theresist film in addition to the foregoing kinds of defects, it ispossible, for example, to design a mask pattern so as to avoid thedefect in the manufacture of a mask or to deal with it by applying theresist film to a mask blank with a grade in which the defect is notquestioned. As the forming conditions of the resist film, there is citeda coating apparatus, spin coating condition, heating condition, heater,cooling condition, cooler, resist film forming date, resist film formingenvironment, or the like.

As a manner of using the resist film information, the following usingmanner is specifically considered. The marking step forms the marker foridentifying a resist film to be formed on the mask pattern thin film,the mask blank manufacturing method includes the resist film formingstep of forming the resist film on the mask pattern thin film and theresist film inspection step of inspecting, for example, at least one ofthe in-plane thickness uniformity and the defect being the resist filminformation of the formed resist film, the resist film inspection stepincluding a pass/fail judging step of judging whether or not aspecification of the mask blank is satisfied, and the mask blankmanufacturing method further includes a resist film stripping step ofstripping the resist film from the mask blank that has been judged notto satisfy the specification of the mask blank, a resist identifyingstep of identifying, by the use of the information read from the marker,the resist film to be formed on the mask pattern thin film on the glasssubstrate that has been stripped of the resist film in the resist filmstripping step, and a resist film re-forming step of forming on the maskpattern thin film the resist film identified in the resist identifyingstep.

According to the manner as described above, even when, for example, afailure occurs in coating the resist film, it is possible to properlyrecoat/re-form a resist film. Further, since the resist film to bere-formed can be reliably selected, the management of the steps can besimplified.

(Structure 11)

A method of manufacturing a mask blank for obtaining a new mask blank byusing a manufactured mask blank having a mask pattern thin film on amask blank glass substrate and a resist film on the mask pattern thinfilm,

wherein the mask blank glass substrate is formed, on a mirror-likesurface in an area, having no influence on transfer, on a surface of themask blank glass substrate, with a marker for identifying or managingthe mask blank glass substrate and/or the mask blank, the marker beingformed by irradiation of laser light, and

the marker is correlated with information including at least one ofsubstrate information about the mask blank glass substrate, thin filminformation about the mask pattern thin film, and resist filminformation about the resist film,

the method comprising:

a film stripping step of stripping the resist film of the manufacturedmask blank or the resist film and the mask pattern thin film of themanufactured mask blank;

a film re-forming step of forming a resist film other than the strippedfilm or a mask pattern thin film and a resist film other than thestripped films; and

a step of obtaining at least one of resist film information about theresist film and thin film information about the mask pattern thin filmformed in the film re-forming step,

wherein at least one of the resist film information and the thin filminformation is correlated with the marker.

The film stripping step specifically represents, for example, a resistfilm stripping step or a thin film stripping step.

Further, a mask blank manufacturing method for manufacturing a new maskblank by the use of a manufactured mask blank having, on a mask blankglass substrate, a mask pattern thin film to be formed into a maskpattern, a resist film formed on the mask pattern thin film, and amarker for identifying the resist film, a marker for identifying themask pattern thin film, or a marker for identifying the glass substrate,comprises a preparation step of preparing the manufactured mask blank, aresist film stripping step of stripping the resist film from themanufactured mask blank, a resist film selection step of selecting, bythe use of information read from the marker, a resist film to be formedon the manufactured mask blank, and a resist film re-forming step offorming on the mask pattern thin film the resist film selected in theresist film selection step.

According to the manner as described above, even if a sensitivity change(degradation or the like) occurs in the resist film of the manufacturedmask blank, the mask blank can be efficiently recycled. Further, sincethe marker is formed on the mask blank itself, it is possible tocorrelate between the information about the mask blank and the maskblank. This can simplify the management of the steps.

(Structure 12)

A mask blank manufacturing method according to Structure 11, wherein:

the marker has a pit shape formed by irradiating the laser light ontothe mirror-like surface in the area, having no influence on transfer, onthe surface of the mask blank glass substrate.

This makes it possible to form the marker with a very small possibilityof generating dust.

(Structure 13)

A method according to Structure 11, wherein:

the resist film is a chemically amplified resist film, and

a mask blank after the lapse of a predetermined time from coating of theresist film is prepared as the manufactured mask blank.

This makes it possible to properly recycle even the mask blank using thechemically amplified resist film that quickly changes in sensitivity.The chemically amplified resist film often largely changes insensitivity in a short time, for example, about two weeks. If a mask ismanufactured by the use of the mask blank formed with the resist filmwhose change in sensitivity is large, CD variation of a formed maskpattern undesirably becomes large. In the case of a normal resist film,a time period in which a change in sensitivity becomes large is, forexample, about one month to three months.

(Structure 14)

A method of producing a mask, comprising:

a step of patterning the mask pattern thin film of the mask blankobtained by the method according to Structure 5 to thereby form a maskpattern on the mask blank glass substrate.

According to the Structure 14, the mask blank information is obtainedvia the marker so that one-by-one management can be reliably achievedthroughout manufacture from the mask blank to the mask.

(Structure 15)

A mask blank glass substrate, comprising:

a pit on a mirror-like surface in an area, having no influence ontransfer, on a surface of the mask blank glass substrate,

the pit being formed by irradiation of laser light and used as a markerfor identifying or managing the mask blank glass substrate and/or a maskblank formed with a mask pattern thin film on the mask blank glasssubstrate.

(Structure 16)

A mask blank glass substrate according to Structure 15, wherein:

the pit is formed in an area outside an optical path of inspectionlight, which checks at least a defect existing in a pattern formingarea, on an end surface perpendicular to a main surface, where the maskpattern thin film is formed, of the mask blank glass substrate.

Since the pit is formed in the area outside the optical path of theinspection light, which checks at least a defect existing in the patternforming area, on the end surface of the mask blank glass substrate, thepit does not obstruct the inspection light. Therefore, the mask blankglass substrate or the mask blank with a guarantee for the defectivequality can be obtained.

(Structure 17)

A mask blank glass substrate, comprising:

a pit in an area of 10 mm or less from a corresponding one of fourcorners of the mask blank glass substrate on an end surfaceperpendicular to a main surface, where a mask pattern thin film tobecome a transfer pattern is to be formed, of the mask blank glasssubstrate, while excluding an area of 1.2mm from both sides of the mainsurface,

the pit being formed by irradiation of laser light and used as a markerfor identifying or managing the mask blank glass substrate and/or a maskblank formed with the mask pattern thin film on the mask blank glasssubstrate.

This makes it possible to obtain the same effect as Structure 1 or 15.Further, in case where a resist film is formed on the mask pattern thinfilm by the spin coating method, it is possible to prevent degradationof the in-plane thickness uniformity of the resist film caused by thepit formed on the end surface of the glass substrate.

(Structure 18)

A mask blank glass substrate according to Structure 15 or 17, wherein:

an opening width (L1) of the pit is 150 μm or more, a depth (D) of thepit is 10 μm or more, and a ratio (L1/D) between the opening width andthe depth is 10 or more.

This makes it possible to ensure sufficient reading accuracy and,further, to suppress generation of dust because the inside of the pitcan be easily cleaned by the use of a side brush or the like.

The surface roughness of the pit is preferably different from that ofthe mirror-like surface of the glass substrate and is, for example,preferably set in the range of 0.1 to 5 nm in Ra (arithmetic averagesurface roughness) and more preferably 0.1 to 2 nm. Arithmetic averagesurface roughness Ra follows Japanese Industrial Standard (JIS) B0601.The surface roughness of the pit is, specifically, a surface roughnessof a bottom portion of the pit.

An annular convex portion may be formed at the periphery of an openingportion of the pit so as to surround the opening portion of the pit.With this structure, it is possible to enhance the reading accuracy ofthe marker. Therefore, for example, even when the depth of the pit isshallow, the marker can be read with sufficiently high accuracy. Whenthe depth of the pit is shallow, a polishing amount required fordeleting the marker is reduced. Accordingly, with this structure, when,for example, the mask blank glass substrate is recycled, the marker canbe easily changed. It is preferable that the annular convex portion beformed so as to rise smoothly. The height of the convex portion ispreferably set to 0.05 to 5 μm and more preferably 0.05 to 1 μm.

(Structure 19)

A mask blank glass substrate according to Structure 15 or 17, wherein:

the marker is correlated with substrate information about the mask blankglass substrate.

(Structure 20)

A mask blank, comprising:

the mask blank glass substrate according to Structure 15 or 17, and

a mask pattern thin film to be formed into a mask pattern, the maskpattern thin film being formed on the mask blank glass substrate.

(Structure 21)

A mask blank according to Structure 20, wherein:

the marker is correlated with information including at least one ofsubstrate information about the mask blank glass substrate, thin filminformation about the mask pattern thin film, and resist filminformation about a resist film formed on the mask pattern thin film.

(Structure 22)

A mask comprising:

the mask blank glass substrate according to Structure 15; and

a mask pattern formed on the mask blank glass substrate.

According to this invention, a marker with a very small possibility ofgenerating dust can be formed on a mask blank glass substrate, Further,it is possible to efficiently recycle a mask blank glass substrate or amask blank. Further, a mask blank glass substrate or a mask blank with aguarantee for the defective quality can be obtained. Further, in thecase of forming a resist film on a thin film for a mask pattern by thespin coating method, a mask blank glass substrate or a mask blank thatprevents degradation of the in-plane thickness uniformity of the resistfilm caused by a marker formed on an end surface can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show one example of a structure of a mask blankaccording to a preferred embodiment of this invention, wherein FIG. 1Ais a side view of the mask blank and FIG. 1B is a diagram showing oneexample of a structure of a marker;

FIG. 2 is a diagram showing one example of a detailed shape of a pit ofthe marker;

FIG. 3 is a flowchart showing one example of a manufacturing method ofthe mask blank; and

FIG. 4 is a flowchart showing one example of a manufacturing method formanufacturing a new mask blank by the use of the manufactured maskblank.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Now, a preferred embodiment according to this Invention will bedescribed with reference to the drawings.

FIGS. 1A and 1B show one example of a structure of a mask blank 10according to the embodiment of this invention. FIG. 1A is a side view ofthe mask blank 10. In this example, the mask blank 10 is a mask blankfor an exposure light source with a wavelength of 200 nm or less, suchas, for example, an ArF excimer laser (wavelength: 193 nm) or an F₂excimer laser (wavelength: 157 nm), and comprises a glass substrate 12,a thin film 14 for a mask pattern, and a resist film 16.

The glass substrate 12 is a glass substrate for a mask blank and is madeof a substrate material such as a synthetic quartz glass. The glasssubstrate 12 has main surfaces and end surfaces (side surfaces andchamfered surfaces) that are each polished to a predetermined surfaceroughness so as to be a mirror surface (e.g. arithmetic average surfaceroughness Ra is 1 nm or less). Further, in this example, the glasssubstrate 12 has, at a portion of the end surface, a marker 18 which isused for identification or management of the glass substrate 12. By theuse of the marker 18, the glass substrate 12 or the mask blank 10 isone-by-one managed.

The mask pattern thin film 14 is a thin film such as a light-shieldingfilm or a phase shift film. The mask pattern thin film 14 is patternedinto a mask pattern in the manufacturing process of a mask. The resistfilm 16 is formed on the mask pattern thin film 14.

FIG. 1B shows one example of a structure of the marker 18. In thisexample, the marker 18 is a two-dimensional code and has a plurality ofhollows or pits 20 forming respective points of the two-dimensionalcode. Each pit 20 is formed by melting or sublimating part of the endsurface of the glass substrate 12 by irradiation of laser light.

In this example, the marker 18 represents identification informationunique to the glass substrate 12. Further, this identificationinformation is correlated with information, for example, about thesurface shape, flatness, defect, and so on obtained in the manufacturingprocess of the mask blank 10.

FIG. 2 shows one example of a detailed shape of the pit 20. In thisexample, each pit 20 is a hole formed by a laser marker using a carbondioxide (CO₂) gas laser. An opening portion of the pit 20 has agenerally circular shape. Further, an annular convex portion is formedat the periphery of the opening portion of the pit 20 so as to smoothlyrise from the end surface of the glass substrate 12, thereby surroundingthe opening portion of the pit 20. By forming the opening portion inthis manner, it is possible to enhance the reading accuracy of themarker 18 (see FIGS. 1A and 1B). The opening portion of the pit 20 mayhave a polygonal shape such as a square shape or a polygonal shape withrounded corners.

Herein, an opening width L1 of the pit 20 is, for example, 100 to 500 μmand more preferably about 150 to 300 μm. A bottom width L2 of the pit 20is, for example, 10 to 450 μm and more preferably about 30 to 250 μm. Awidth L3 of an inclined portion of the pit 20 is, for example, 5 to 75μm and more preferably about 15 to 60 μm. A depth D of the pit 20 is,for example, 3 to 20 μm and more preferably about 5 to 15 μm. The heightof the rise of the opening portion of the pit 20 is, for example, 0.05to 5 μm and more preferably about 0.05 to 1 μm. Further, the surfaceroughness of the pit 20 is, for example, 0.1 to 5 nm in Ra (arithmeticaverage surface roughness) and more preferably 0.1 to 2 nm.

In order to ensure the sufficient reading accuracy and, further, easilyclean the inside of the pit 20 by the use of a side brush or the like tothereby suppress the generation of dust, it is preferable that theopening width L1 of the pit 20 be 150 μm or more, the depth D of the pit20 be 10 μm or more, and the ratio (L1/D) between the opening width andthe depth of the pit 20 be 10 or more.

The glass substrate 12 is subjected to a defect inspection for checkingthe presence of a convex defect (particles or the like), a concavedefect (pinholes, cracks, or the like), striae, bubbles, abnormality intransmittance due to the incorporation of impurities, or the like atleast in an area where the mask pattern is formed. For example, aninspection method as described in Japanese Patent No. 3422935 is carriedout for checking the presence of the convex or concave defect on thesurfaces of the glass substrate 12 or the presence of the striae orbubbles inside the glass substrate 12. In this inspection method, withrespect to both main surfaces of the glass substrate 12 and at least thepair of side surfaces perpendicular to the main surfaces, inspectionlight (laser light) is introduced from the chamfered surface locatedbetween the main surface and the side surface under the condition thatthe inspection light propagates inside the glass substrate 12 whilesatisfying the total reflection condition, thereby checking the presenceof the foregoing defect by detecting leaking light caused by leakage ofthe inspection light due to deviation from the total reflectioncondition owing to the convex or concave defect. On the other hand, inorder to check the presence of the abnormality in transmittance due tothe incorporation of impurities in the glass substrate 12, light havingthe exposure wavelength is introduced from the side surface of the glasssubstrate 12 and, by receiving light having a wavelength longer than theexposure wavelength, which is emitted from the internal defect of theglass substrate 12 due to the introduced light having the exposurewavelength, the internal defect is inspected based on the quantity ofthe received light. In either of the inspection methods as describedabove, the inspection light hits on the side surfaces of the glasssubstrate 12. Therefore, if the pits as the marker are formed on theside surface, where the inspection light is adapted to hit, of the glasssubstrate 12, the defect inspection cannot be carried out or, even if itcan be carried out, the sufficient inspection accuracy cannot beobtained. Accordingly, the pits as the marker are preferably formed at aposition in an area outside the optical path of the inspection light,which checks at least the defect existing in the pattern forming area,on the side surface being the end surface perpendicular to the mainsurface where the mask pattern thin film is formed. Specifically, in theglass substrate 12 having a size of 152.4 mm×152.4 mm×6.35 mm, it ispreferable to form the pits as the marker at a position outside a centerportion of 132 mm on the side surface of the glass substrate 12, i.e. inan area of 10 mm or less from a corresponding one of four corners of theglass substrate 12.

It is more preferable to form the pits as the marker in the area of 10mm or less from the corresponding one of the four corners of the glasssubstrate 12 while excluding an area of 1.2 mm from both sides of themain surface of the glass substrate 12. By forming the pits as themarker at the foregoing specified position, in the case of forming theresist film on the mask pattern thin film by the spin coating method, itis possible to prevent degradation of the in-plane thickness uniformityof the resist film on the mask pattern thin film.

FIG. 3 is a flowchart showing one example of a manufacturing method ofthe mask blank 10. Except what will be described hereinbelow, respectivesteps of the manufacturing method are the same as or similar to those ina known mask blank manufacturing method. In this example, at first, aglass substrate 12 with chamfered end surfaces is lapped by the use of aboth-side lapping machine (lapping step S102).

Then, the end surfaces and the main surfaces of the glass substrate 12are polished by the use of a both-side polishing machine (polishing stepS104) and cleaning is carried out after the polishing (cleaning stepS106). In the polishing step S104, the end surfaces and the mainsurfaces of the glass substrate 12 are subjected; for example, to roughpolishing, precise polishing, and ultra-precise polishing so as to befinished to mirror surfaces each having, for example, a surfaceroughness of 0.2 nm or less in RMS (root mean square roughness).

Then, a substrate inspection is carried out to obtain information aboutthe surface shape, flatness, and defect of the glass substrate 12(substrate inspection step S108). The substrate inspection step S108checks, for example, the thickness, the flatness, the warp shape of themain surface (the convex-concave state of the entire main surface), andso on with respect to the surface shape of the glass substrate 12.Further, with respect to the defect of the glass substrate 12, thesubstrate inspection step S108 checks, for example, the position, kind,size, and so on of the defect. In this case, the size of the defect isdistinguished, for example, among 0.2 μm or less, 0.2 to 0.5 μm, 0.5 to1 μm, and 1 μm or more. By distinguishing the size of the defect in thismanner, the grade of the glass substrate 12 can be properly classified.

Then, by the use of, for example, a laser marker of a carbon dioxide gaslaser, part of the end surface of the glass substrate 12 is melted orsublimated by irradiation of laser light to thereby form each of pits 20of a marker 18 (marking step S110). The marker 18 representsidentification information unique to the glass substrate 12. Further,this identification information is correlated with the inspectionresults of the substrate inspection step S108. Thus, by the use of themarker 18, it is possible to identify the shape of the glass substrate12, such as the thickness, flatness, warp shape, and so on, and theposition, kind, size, and so on of the defect. Therefore, according tothis example, the formation of a mask pattern thin film 14 and so on canbe efficiently carried out. Further, for example, in the manufacture ofa mask, a mask pattern can be designed so as to avoid the defect.

In the marking step S110, the laser light may be irradiated a pluralityof times with respect to each of the pits 20 in the marker 18. This canreduce variation in shape of the pits 20 and thus improve the readingaccuracy of the marker 18.

Then, the marker 18 is read and, based on the read marker 18, adetermination is made of the mask pattern thin film 14 to be formed onthe glass substrate 12 (thin film determining step S112). In thisexample, the thin film determining step S112 identifies the surfaceshape of the glass substrate 12 from the inspection results of thesubstrate inspection step S108 correlated with the marker 18. Then,according to the identified shape such as, for example, the warp shapeof the main surface, a selection is made of the type of a mask blanksuitable for use of the glass substrate 12. Based on it, the thin filmdetermining step S112 determines a light-shielding film, alight-shielding film and a phase shift film, or the like necessary forsuch a mask blank to be the mask pattern thin film 14 to be formed.

According to this example, the type of the mask pattern thin film 14 canbe determined based on the inspection results of the substrateinspection step S108. Therefore, the glass substrate 12 can beeffectively used without waste.

In this example, the thin film determining step S112 further correlatesinformation indicative of a resist film 16 to be used in the selectedmask blank 10 with the identification information of the marker 18.Thus, by the use of the marker 18, the resist film 16 to be coated onthe mask pattern thin film 14 can be further identified.

Next to the thin film determining step S112, the determined mask patternthin film 14 is formed, on the main surface of the glass substrate 12,to a thickness that can achieve the required optical properties (filmforming step S114) and, then, the formed mask pattern thin film 14 isinspected (thin film inspection step S116). In this example, the thinfilm inspection step S116 includes a pass/fail judging step and judgeswhether or not the formed mask pattern thin film 14 satisfies aspecification of the mask blank. When it has passed the inspection ofthe thin film inspection step S116 (S116: Pass), the resist film 16 iscoated (formed) on the mask pattern thin film 14 (resist film formingstep S118) and, then, the coated resist film 16 is inspected (resistfilm inspection step S120). The resist film inspection step S120includes a pass/fail judging step and judges whether or not the coatedresist film 16 satisfies a specification of the mask blank. If it passesthe inspection of the resist film inspection step S120 (S120: Pass), themask blank 10 is completed.

The thin film inspection step S116 and the resist film inspection stepS120 each perform the inspection for the specification which affectspattern transfer, such as, for example, that the number of defects(pinholes or particles) of 0.2 μm or more is only several or less. Thethin film inspection step S116 further inspects, for example, for thepredetermined optical properties (transmittance etc.).

When it has failed in the thin film inspection step S116 (S116: Fail),the mask pattern thin film 14 is stripped from the glass substrate 12(thin film stripping step S206). Then, the marker 18 of the glasssubstrate 12 is read and the thickness of the glass substrate 12 isidentified from the inspection results of the substrate inspection stepS108 correlated with the read marker 18 (thickness identifying stepS208). If the glass substrate 12 has the thickness that enablesrecycling by repolishing (S210: Yes), the glass substrate 12 isrepolished by a polishing amount that is determined according to thethickness identified in the thickness identifying step S208 (repolishingstep S212). For example, based on the identified thickness, therepolishing step S212 classifies the glass substrate 12 into one ofgroups sorted by thickness and polishes the glass substrate 12 by thepolishing amount that is preset for that group.

Then, after the repolishing, the method returns to the cleaning stepS106 and repeats the subsequent steps. In this case, the marking stepS110 forms a marker 18 for identifying the glass substrate 12 recycledby the repolishing. Further, the film forming step S114 forms a new maskpattern thin film 14 on the main surface of the glass substrate 12polished in the repolishing step S212. According to this example, theexpensive glass substrate 12 can be effectively used without waste.

The step S210 judges whether or not the glass substrate 12 can berecycled, based on whether or not the minimum thickness determined for amask blank glass substrate remains after the glass substrate 12 isrepolished by a machining amount that is minimally required forsatisfying the quality. When it is judged not to be recyclable due tothe insufficient thickness (S21 0: No), the glass substrate 12 isdiscarded.

On the other hand, when it has failed in the resist film inspection stepS120 (S120: Fail), the resist film 16 is stripped from the glasssubstrate 12 (resist film stripping step S202) and, then, it is judgedwhether or not repolishing is necessary for recycling of the glasssubstrate 12 (S204). The step S204 judges the repolishing to benecessary when, for example, the resist film inspection cannot be passedeven by recoating a resist film 16 a predetermined number of times. Thestep S204 may judge whether or not the repolishing is necessary, basedon the inspection results of the substrate inspection step S108.

When the repolishing is judged unnecessary (S204: No), the marker 18 isread and, based on the read marker 18, a selection is made of a resistfilm 16 to be coated on the mask pattern thin film 14 (resist selectionstep S214). Then, the selected resist film 16 is coated on the maskpattern thin film 14 (resist re-forming step S216) and the methodproceeds again to the resist film inspection step S120. According tothis example, even when coating/formation of the resist film 16 isunsuccessful, recoating/re-formation thereof can be properly carriedout. Further, since the resist film 16 to be recoated/re-formed can bereliably selected, the management of the steps can be simplified.

On the other hand, when the repolishing is judged necessary (S204: Yes),the thin film stripping step S206 and the subsequent steps are repeated.This makes it possible to recycle the glass substrate 12 that cannot berecycled only by recoating/re-forming the resist film 16.

Although omitted in the foregoing description, it is preferable that thesubstrate inspection step S108 further judge, for example, whether ornot the glass substrate 12 satisfies the required quality. In this case,if it is judged that the required quality is not satisfied, the method,for example, proceeds to the marking step S110 where the marker 18 isformed and, then, proceeds to the thickness identifying step S208 andthe subsequent steps for repolishing the glass substrate 12. This makesit possible to use the glass substrate 12 more effectively withoutwaste. For example, in the case of a glass substrate for a mask blankfor ArF excimer laser exposure, the required quality in the glasssubstrate 12 represents a specification relating to the glass substratewhich affects pattern transfer, such as, for example, that the surfaceroughness is 0.2 nm or less in RMS, the flatness is 0.5 μm or less, orthere is no defect of 0.2 μm or more.

FIG. 4 is a flowchart showing one example of a manufacturing method formanufacturing a new mask blank 10 by the use of the manufactured maskblank 10. In this example, the mask blank 10 has a chemically amplifiedresist film formed as the resist film 16.

In this example, at first, the manufactured mask blank 10 is prepared,for example, by recovery from a mask maker (preparation step S302). Forexample, the preparation step S302 prepares, as the manufactured maskblank 10, a mask blank 10 after the lapse of a predetermined time (e.g.one month or more) from the coating of the resist film 16. Thepreparation step S302 may prepare a plurality of types of mask blanks 10formed with different resist films 16, respectively.

Then, the resist film 16 of the mask blank 10 is stripped (resist filmstripping step S304). In the resist film stripping step S304, the resistfilms 16 of the plurality of types of mask blanks 10 may besimultaneously stripped.

Then, the marker 18 is read and, based on the read marker 18, aselection is made of the resist film 16 that was formed in the maskblank 10 before the stripping of the resist film (resist selection stepS306). Then, the selected resist film 16 is coated (formed) on the maskpattern thin film 14 (resist re-forming step S308).

Accordingly, even when the resist film 16 of the manufactured mask blank10 is degraded or the like, the mask blank 10 can be efficientlyrecycled. Further, the management of the steps can be simplified by theuse of the marker 18.

Example 1

100 mask blank glass substrates for ArF excimer laser exposure weremanufactured according to Example 1. On an end surface of each glasssubstrate, a marker like that shown in FIG. 1B was formed by a lasermarker using a carbon dioxide (CO₂) gas laser. The output of the lasermarker was set to 20 mW/shot and each pit was formed by one shot. Thesize of the entire marker was set to 3.25 mm×3.5 mm. The steps, exceptthe formation of the marker, were the same as those in manufacturing theknown mask blank glass substrate for ArF excimer laser exposure. Theseglass substrates were inspected in the substrate inspection step and allof them satisfied the quality required for the mask blank glasssubstrate for ArF excimer laser exposure.

Comparative Example

Comparative Example was the same as Example 1 except that a YAG laserwas used instead of the carbon dioxide (CO₂) gas laser. 100 mask blankglass substrates for ArF excimer laser exposure were manufacturedaccording to Comparative Example. These glass substrates were inspectedin the substrate inspection step and only 27% of them (i.e. 27 glasssubstrates) satisfied the quality required for the mask blank glasssubstrate for ArF excimer laser exposure.

Example 2

A marker was formed on a side surface being an end surface of each ofmask blank glass substrates under the same conditions as those inExample 1. Each glass substrate had a size of 152.4 mm×152.4 mm×6.35 mm.As shown in the figure, the marker was formed to a size of 3 mm×3 mmhaving its center position located 7 mm away from a corner of the glasssubstrate where a glass notch mark was formed and 3.18 mm away from themain surface of the glass substrate. The opening width L1 of each ofpits forming the marker was 170 μm, the depth D thereof was 17 μm, andthus the ratio (L1/D) between the opening width and the depth was 10.After forming the pits as the markers, the end surfaces of the glasssubstrates were cleaned by the use of a cleaning brush and then thedefect inspection was carried out for the glass substrates. As a result,all of them satisfied the quality required for the mask blank glasssubstrate for ArF excimer laser exposure. Further, a mask pattern thinfilm was formed on each of the glass substrates and then a resist film(average thickness: 3000 Å) was formed on the mask pattern thin film bythe spin coating method. Thus, mask blanks for ArF excimer laserexposure were obtained. The in-plane thickness uniformity of the resistfilm of each mask blank was measured. The in-plane thickness uniformityof the resist film was derived in the following manner. The thickness ofthe resist film was measured at (11×11=121 points) uniformly arrangedover an entire guarantee area of 132 mm×132 mm (mask pattern formingarea) at the center of the glass substrate by the use of a spectralreflection type thickness gauge (AFT6100M manufactured by NanometricsJapan Ltd.) to thereby derive an in-plane thickness distribution(thickness data at the respective measurement points). From the derivedin-plane thickness distribution data, the in-plane thickness uniformitywas derived as “(maximum thickness value)−(minimum thicknessvalue)=(in-plane thickness uniformity)”. As a result, the in-planethickness uniformity of each resist film was as small as 22 Å and thuswas quite excellent. Further, a mask was manufactured by the use of eachmask blank and the CD accuracy of the obtained mask satisfied thequality required for the mask for ArF excimer laser exposure.

While this invention has been described in terms of the preferredembodiment, the technical scope of this invention is not to be limitedthereto. It is readily understood by persons skilled in the art thatvarious modifications or improvements can be added to the foregoingembodiment. It is obvious from the recitation of claims that the modesadded with those modifications or improvements can also be included inthe technical scope of this invention.

This invention is suitably applicable to, for example, a mask blankglass substrate and a mask blank.

1. A method of manufacturing a mask blank glass substrate, comprising: amarking step of irradiating laser light onto a mirror-like surface in anarea, having no influence on transfer, on a surface of the mask blankglass substrate to thereby form a pit that is used as a marker foridentifying or managing the mask blank glass substrate.
 2. A methodaccording to claim 1, further comprising: a step of preparing substrateinformation about the mask blank glass substrate, wherein the substrateinformation is correlated with the marker.
 3. A method according toclaim 2, wherein: the substrate information is information including atleast one of physical properties, chemical properties, opticalproperties, a surface form, a surface shape, a material, and a defect ofthe mask blank glass substrate.
 4. A method of manufacturing a maskblank, comprising: a film forming step of forming a mask pattern thinfilm on a main surface of the mask blank glass substrate obtained by themethod according to claim
 1. 5. A method of manufacturing a mask blank,comprising: a film forming step of forming a mask pattern thin film on amain surface of a glass substrate, and a marking step of irradiatinglaser light onto a mirror-like surface in an area, having no influenceon transfer, on a surface of the glass substrate to thereby form a pitthat is used as a marker for identifying or managing the glass substrateand/or a mask blank formed with the mask pattern thin film on the glasssubstrate.
 6. A method according to claim 5, further comprising: a stepof preparing substrate information about the glass substrate before thefilm forming step, the marker being correlated with the substrateinformation, and a thin film determining step of determining the maskpattern thin film to be formed, based on the substrate information readfrom the marker, wherein the film forming step forms the mask patternthin film determined in the thin film determining step.
 7. A methodaccording to claim 5, further comprising: a thin film informationpreparing step of preparing thin film information about the mask patternthin film after the film forming step, wherein the marker is correlatedwith the thin film information obtained in the thin film informationpreparing step.
 8. A method according to claim 7, wherein: the thin filminformation is information including at least one of physicalproperties, chemical properties, electrical properties, opticalproperties, a surface form, a material, a defect, and a film formingcondition of the mask pattern thin film.
 9. A mask blank manufacturingmethod according to claim 5, further comprising: a resist film formingstep of forming a resist film on the mask pattern thin film after thefilm forming step, and a resist film information preparing step ofpreparing resist film information about the resist film, wherein themarker is correlated with the resist film information obtained in theresist film information preparing step.
 10. A method according to claim9, wherein: the resist film information is information including atleast one of physical properties, chemical properties, a surface form, amaterial, a defect, and a film forming condition of the resist film. 11.A method of manufacturing a mask blank for obtaining a new mask blank byusing a manufactured mask blank having a mask pattern thin film on amask blank glass substrate and a resist film on the mask pattern thinfilm, wherein the mask blank glass substrate is formed, on a mirror-likesurface in an area, having no influence on transfer, on a surface of themask blank glass substrate, with a marker for identifying or managingthe mask blank glass substrate and/or the mask blank, the marker beingformed by irradiation of laser light, and the marker is correlated withinformation including at least one of substrate information about themask blank glass substrate, thin film information about the mask patternthin film, and resist film information about the resist film, the methodcomprising: a film stripping step of stripping the resist film of themanufactured mask blank or the resist film and the mask pattern thinfilm of the manufactured mask blank; a film re-forming step of forming aresist film other than the stripped film or a mask pattern thin film anda resist film other than the stripped films; and a step of obtaining atleast one of resist film information about the resist film and thin filminformation about the mask pattern thin film formed in the filmre-forming step, wherein at least one of the resist film information andthe thin film information is correlated with the marker.
 12. A maskblank manufacturing method according to claim 11, wherein: the markerhas a pit shape formed by irradiating the laser light onto themirror-like surface in the area, having no influence on transfer, on thesurface of the mask blank glass substrate.
 13. A method according toclaim 11, wherein: the resist film is a chemically amplified resistfilm, and a mask blank after the lapse of a predetermined time fromcoating of the resist film is prepared as the manufactured mask blank.14. A method of producing a mask, comprising: a step of patterning themask pattern thin film of the mask blank obtained by the methodaccording to claim 5 to thereby form a mask pattern on the mask blankglass substrate.
 15. A mask blank glass substrate, comprising: a pit ona mirror-like surface in an area, having no influence on transfer, on asurface of the mask blank glass substrate, the pit being formed byirradiation of laser light and used as a marker for identifying ormanaging the mask blank glass substrate and/or a mask blank formed witha mask pattern thin film on the mask blank glass substrate.
 16. A maskblank glass substrate according to claim 15, wherein: the pit is formedin an area outside an optical path of inspection light, which checks atleast a defect existing in a pattern forming area, on an end surfaceperpendicular to a main surface, where the mask pattern thin film isformed, of the mask blank glass substrate.
 17. A mask blank glasssubstrate, comprising: a pit in an area of 10mm or less from acorresponding one of four corners of the mask blank glass substrate onan end surface perpendicular to a main surface, where a mask patternthin film to become a transfer pattern is to be formed, of the maskblank glass substrate, while excluding an area of 1.2mm from both sidesof the main surface, the pit being formed by irradiation of laser lightand used as a marker for identifying or managing the mask blank glasssubstrate and/or a mask blank formed with the mask pattern thin film onthe mask blank glass substrate.
 18. A mask blank glass substrateaccording to claim 15 or 17, wherein: an opening width (L1) of the pitis 150 μm or more, a depth (D) of the pit is 10 μm or more, and a ratio(L1/D) between the opening width and the depth is 10 or more.
 19. A maskblank glass substrate according to claim 15 or 17, wherein: the markeris correlated with substrate information about the mask blank glasssubstrate.
 20. A mask blank, comprising: the mask blank glass substrateaccording to claim 15 or 17, and a mask pattern thin film to be formedinto a mask pattern, the mask pattern thin film being formed on the maskblank glass substrate.
 21. A mask blank according to claim 20, wherein:the marker is correlated with information including at least one ofsubstrate information about the mask blank glass substrate, thin filminformation about the mask pattern thin film, and resist filminformation about a resist film formed on the mask pattern thin film.22. A mask comprising: the mask blank glass substrate according to claim15; and a mask pattern formed on the mask blank glass substrate,